Silicone Elastomer Dispersion Using C18 Surfactant for Stable Emulsions

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Solution Overview

Problem

Conventional surfactants used in aqueous dispersions of silicone elastomer particles either cause skin irritation or have inadequate emulsifying ability, leading to instability and poor performance in cosmetics.

Innovation Solution

Aqueous dispersion comprising silicone elastomer particles with a polyoxyethylene alkyl ether having an alkyl group with 18 carbon atoms and a hydrophile-lipophile balance (HLB) of 12.8 to 15.1, providing improved stability and reduced skin irritation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional surfactants (polyoxethylene alkyl phenyl ethers or polyoxethylene alkyl ethers with smaller alkyl groups) are used to prepare aqueous dispersion of silicone elastomer particles, then emulsifying ability is improved, but skin irritation increases and endocrine disturbance occurs

Engineering Contradiction:

Improveemulsifying abilityVSAvoidskin irritation and endocrine disturbance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the carbon atom number parameter of the alkyl group from conventional 8-13 carbon atoms to 18 carbon atoms, and adjusts the HLB value to 12.8-15.1 range. This parameter change resolves the contradiction by providing sufficient emulsifying ability while reducing skin irritation and eliminating endocrine disturbance effects.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite surfactant system comprising polyoxethylene alkyl ether with specifically 18 carbon atoms in the alkyl group, combined with polyoxethylene sorbitan monolaurate. This composite approach achieves synergistic emulsifying effect while maintaining low skin irritation and avoiding endocrine disturbance.

Inventive Principle:

Principle #40Composite materials

2Reliability

If polyoxethylene alkyl ethers with smaller number of carbon atoms in alkyl groups are used, then emulsifying ability is improved, but skin irritation increases

Engineering Contradiction:

Improveemulsifying abilityVSAvoidskin irritation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent increases the carbon atom number of the alkyl group from conventional smaller values (8-13) to 18 carbon atoms. This parameter change reduces skin irritation while maintaining effective emulsifying ability through the optimized HLB value range of 12.8-15.1.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If ionic surfactants are used to improve storage stability, then storage stability is improved, but skin irritation increases

Engineering Contradiction:

Improvestorage stabilityVSAvoidskin irritation

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces ionic surfactants with nonionic polyoxethylene alkyl ether and polyoxethylene sorbitan monolaurate. This substitution eliminates skin irritation associated with ionic surfactants while maintaining adequate storage stability through the selected surfactant combination and ratios.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent employs a composite surfactant system combining polyoxethylene alkyl ether (18 carbon atoms) with polyoxethylene sorbitan monolaurate. This composite provides both storage stability and low skin irritation, resolving the contradiction between stability and safety.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution achieves a stable emulsion with improved skin compatibility and cosmetic performance, including better spreadability and feel, while maintaining effective emulsification.

Implementation Method 1

an aqueous dispersion comprising (A) silicone elastomer particles, (B) polyoxethylene alkyl ether, and (C) water

Methodology Applied

Scientific EffectSurfactant: Surfactant

Implementation Method 2

provides a stable emulsion with improved skin compatibility

Methodology Applied

Scientific EffectEmulsion: Emulsion

Data Source

PatentUS9616254B2Aqueous dispersion comprising silicone elastomer particles, a silicone elastomer particle and a cosmetic

Publication Date: 2017.04.11 SHIN ETSU CHEMICAL CO LTD

AI summary

One of the purposes of the present invention is to provide an aqueous dispersion of silicone elastomer particles to provide a stable emulsion and the silicone elastomer particle, wherein a polyoxyethylene alkyl ether which has an alkyl group having a large number of carbon atoms is used as a surfactant. Further, another purpose is to provide a cosmetic comprising said aqueous dispersion or said silicone elastomer particles and giving a good feeling in the use. The present invention provides an aqueous dispersion comprising (A) silicone elastomer particles having a 90% volume cumulative diameter (D90) of 0.3 to 20 μm in an amount of 5 to 80 mass %, based on a total mass of the aqueous dispersion, (B) at least one polyoxyethylene alkyl ether having an alkyl group having 18 carbon atoms in an amount of 0.01 to 15 mass %, based on a total mass of the aqueous dispersion, wherein a hydrophile-lipophile balance (HLB) of the polyoxyethylene alkyl ether is 12.8 to 15.1, and (C) water in an amount of 19 to 94 mass %, based on a total mass of the aqueous dispersion. Further, the present invention provides a material comprising the aforesaid components (A) and (B), a method for preparing the material and a cosmetic comprising the aqueous dispersion or the material.